Your issue is your particle bounds are too small. Bounds essentially say “if the camera isn’t inside this invisible box, and cannot see this invisible box, don’t waste resources rendering the particle.”
What you need to do is duplicate the particle effect used by the standing torch into your mod directory, and then begin modifying your new copied version.
You can visualize bounds by going into your particle effect’s editor and clicking ‘bounds’ up at the top
(it will look something like the blue area)
What you need to do is left click in the black space marked red, and then go down to the details panel in the bottom left (marked in green).
From there, scroll down until you see a check-box called “Use Fixed Relative Bounding Box”, and either check it, or make sure it’s checked.
Now set the minimum / maximum x y z values to shape it to the area your light takes up.
So for example, if I want my lights to cover an area up to 400 units, I would
set the minimum to -300, -300, -300
and set the maximum to 300, 300, 300
(Slightly larger than the range the light would cover just incase).